Movable barriers of various kinds are known in the art, including barriers that pivot and/or move vertically or horizontally. Many such movable barriers can be selectively moved by a movable barrier operator. Such automated systems exist, for example, for use with various kinds of garage doors, sliding and pivoting gates, cross-arm guards, rolling shutters and so forth. In many cases the movable barrier operator for such a system will respond to a remote user interface. So configured, a user can interact with the remote user interface to cause the latter to transmit a command signal to the movable barrier operator and thereby cause a desired movement of a corresponding movable barrier (and/or some other desired action as may be controlled by the operator).
In many instances such a remote user interface comprises a wireless remote control device. In this case the device communicates with the movable barrier operator using a wireless link of choice. Such a design permits considerable flexibility with respect to the convenient use of such a control device. For example, when the movable barrier operator controls a garage door, the wireless remote control device can be carried in a vehicle. The driver can then conveniently access the wireless remote control device from within the vehicle and selectively cause the garage door to close subsequent to having removed the vehicle from within the garage.
Though affording some convenience, it still remains necessary in such a system to physically locate and appropriately interact with the wireless remote control device in order to effect such a desired closing of the movable barrier. Because such systems also usually have a relatively limited transmission range, it is also usually necessary in such a system to take these actions before the vehicle has moved out of effective communications range of the movable barrier operator receiver (or transceiver). It is therefore possible that a driver will be unable to conveniently effect a desired movement of a movable barrier. When this occurs, it is possible that a garage door will be left open for an extended period of time. This can, in turn, pose a number of problems including a security risk to the contents of the garage and of the attached home as well.
There are also some users who generally desire greater convenience and who wish to be able to rely to a greater extent upon such a system. Such users typically prefer to have operation of the movable barrier be automated to a greater extent. One prior art suggestion has been to provide the movable barrier operator with a transmission capability. Such a movable barrier operator can then transmit a status message from time to time. A wireless remote control device having a corresponding reception capability can detect such a status message and make control decisions based upon such messages. For example, upon determining that the remote control device has moved to at least a predetermined distance from the movable barrier operator, the device can then self-initiate transmission of a remote control signal to the movable barrier operator to cause the latter to close the movable barrier.
At least one problem with such an approach again pertains to the limited transmission range of such systems. The maximum transmission power for such systems tends to be quite low due to applicable regulations requiring the transmitted power to be lower for periodic transmissions. This, in turn, renders the development of an effective and reliable control scheme more challenging.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are typically not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.